Also, how are you going to recharge 12kWh of lead-acid batteries?

One reason why NiMH is so good for cars is:

They recharge in the same amount of time they discharge.
Whatever you take out in 5 minutes, can be put back in, in 5 minutes.

Lithium Ion is 2:1. What you take out in 5 minutes, takes 10 minutes to replace.

With Lead Acid, I forget, but the number is either 5:1 or 10:1.
The time required to recharge that many kWh of lead acid often = more hours than you have in a day. ( plus they are darn heavy )